A pneumothorax is an abnormal collection of air in the pleural space that causes an uncoupling of the lung from the chest wall. The main cause of the pneumothorax is lung lesions or pulmonary alveoli ruptures. When the pressure in the pleural cavity increases significantly to oppress the lung tissues, the lung partially or totally collapses which hinders the normal breathing. One of the symptoms of the pneumothorax is dyspnea that affects daily routine and sometimes may cause death.
The pneumothorax can be classified into a traumatic pneumothorax and a spontaneous pneumothorax according to the causes. The traumatic pneumothorax is usually related to trauma, for example, direct damages to the lung due to puncture wounds or indirect damages to the lung due to high impact on the chest. The spontaneous pneumothorax is a common clinical disease caused by many reasons and frequently seen after certain activities which increase the pressure in the chest suddenly and markedly, for example, coughs heavy liftings, exercises, etc. The spontaneous pneumothorax is divided into two types: a primary spontaneous pneumothorax (PSP) and a secondary spontaneous pneumothorax (SSP). The SSP is usually caused by lung diseases, e.g., asthma, pneumonia, or chronic obstructive pulmonary disease (COPD), which result in lung frailty, leading to lung lesions. However the cause of the PSP is unknown and established risk factors include male sex, smoking, and a family history of the pneumothorax.
The spontaneous pneumothorax not only affects the life quality of patients and endangers patients' lives, but also results in a waste of medical resources. Therefore, the treatments of the pneumothorax are not just simply removing the air in the pleural cavity and alleviating the symptoms but preventing pneumothorax from recurring.
There are three principles of the pneumothorax treatment: 1) to remove the air or gas abnormally collected in the pleural cavity; 2) to repair the damaged lung tissues or pulmonary alveoli; and 3) to perform pleurodesis to prevent pneumothorax from recurring. When the pneumothorax is diagnosed for the first time in a young patient, common dealing method is to remove the air abnormally collected in the pleural cavity by chest tube insertion or intercostal catheter drainage. Since these two treatments do not deal with the damaged lung tissues or pulmonary alveoli and no pleurodesis is performed, the chance of recurrence is quite high. Therefore, clinically a pleurodesis surgery is usually suggested to patients to prevent recurrence of the pneumothorax or the pleural effusion. It can be done chemically or surgically. Surgical pleurodesis involves mechanically irritating the parietal pleura, often with a rough pad, to cause the parietal pleura to be slightly inflamed. The inflamed parietal pleura tissues are covered by fibrin secreted by the body to adhere the parietalis pleura onto the visceralis pleura, causing fibrous adhesion so as to prevent the pneumothorax or the pleural effusion. Nevertheless, the pleurodesis causes dramatic pain in the affected part of patients.
Pleural effusion is an abnormal collection of fluid in the pleural space resulting from excessive fluid production, decreased absorption or both. It is the most common manifestation of pleural diseases, with etiologies ranging from cardiopulmonary disorders to symptomatic inflammatory or malignant diseases requiring urgent evaluation and treatment. Approximately 1.5 million patients are diagnosed with pleural effusions in the United States each year (Pleural Effusion, Jeffrey Rubins, MD).
The goal of the pleural treatment is to remove the fluid, to prevent the fluid from building up again, and to determine and treat the problems that cause the buildup of the fluid. Larger effusions may require insertion of an intercostal drain. Repeated effusions may require chemicals, such as bleomycin, tetracycline e.g. minocycline, povidone iodine, or a slurry of talc, or surgical pleurodesis, in which the two pleural surfaces are scarred to each other so that no fluid accumulates between them. This is a surgical procedure that involves the insertion of a chest tube which is required to stay in until the fluid drainage stops. This may take days to weeks and may require prolonged hospitalizations. If the chest tube becomes clogged, the fluid will be left behind and the pleurodesis will fail.
The instilled chemicals cause irritation between the parietal and the visceral layers of the pleura to close off the space between the parietal and the visceral layers, and to prevent the fluid from further accumulating. However, the chemicals may be accompanied by fever, pneumonia, immune rejection, acute respiratory distress syndrome (ARDS), etc.
Therefore, it is necessary to provide a treatment of the pleural abnormalities which reduces pains or infections in patients.